This paper examines relationships between major farm characteristics and U.S. farmers' use of cooperatives in 1986. An ordinal measure of co-op use is developed to classify farmers according to their respective use of cooperatives for marketing farm products or purchasing farm inputs. Logit regression analysis is then used to examine major farm characteristics relative to farmers' co-op use. Statistically significant relationships were found between co-op use and various farm type, size, and location groupings. No statistical significant relationship was found between co-op use and farm operator age.